Structure for absorbing sound



y 1940- J. MAZER STRUCTURE FOR ABSORBING SOUND Filed March 19, 195'? Ta d4: FQVENTOR I m M ATTORNEY Patented July 30, 1940 UNITED STATES PATENT OFFICE STRUCTURE FOR ABSORBING SOUND Jacob Mazer, Miami Beach, Fla.

Application March 19,

Claims.

This invention relates to a material of soundabsorbing qualities intended to be used for acoustical purposes and is a continuation-in-part of certain subject-matter disclosed in my earlier application Serial No. 62,739, filed February 7, 1936.

Broadly speaking, my. invention consists of a layer of compressible material carrying a covering sheet which has an irregular or non-plane surface and which is adapted to undergo certain localizedmovements independent of the movement of the covering sheet as a whole resulting from compression of the-underlying material. In a structure of this type sounds in the lower frequency ranges tend to cause the covering sheet to move bodily and compress the underlying material. However, it has been found that if the covering sheet is approximately fiat and fairly stiff and hard, the sounds of higher frequency may not be satisfactorily absorbed. Since it obviously is desirable to finish a wall with a surface of good appearance, some type of covering sheet is desirable. Accordingly, I use a covering sheet which has portions lying in the plane of the face of the main sheet and portions raised relative thereto. The covering sheet is attached to the main sheet through the portions lying in the lower plane and the raised portions are not'directly attached so they can move relative to the main sheet. It is within the spirit of my invention to have the covering sheet carried by a flat sheet of material such as paper or paper-like material to which is' ailixed the covering sheet which has the raised portions, or where the nature of the underlying compressible sheet permits,

'the intermediate flat sheet of paper or paper-like material may be eliminated.

My invention can readily be understood by reference to the accompanying drawing in which Fig. 1 is a perspective view of one form of device embodying my invention with a portion of the covering sheet broken away; and

Fig. 2 is a perspective view of a modified type of structure,

In the drawing the numeral 20 designates the underlying compressible material which is here in the form of a felt such as rag felt arranged in loops, the ends of which overlie each other as is more fully explained in my Patent No. 2,077,889. Attached as a liner sheet to one set of loops is a facing member [6 which may be formed of paper or a relatively dense type of sheet made by mixing together rag stock and paper stock. In this figure the numeral I8 designates a covering sheet of creped asbestos paper forming irregular ridges 1937, Serial No. 131,855

which will project away from the sheet it when the sheets l6 and I8 are adhesively attached together.

In Fig. 2 the main sheet 22 is a flat sheet of hair felt, to one face of which is attached a 5 molded member 24 having raised portions 26 between which are sunken ridges 28. The sheet 24 is attached to the sheet-22 by the ribs 28 and preferably the two are connected together adhesively. The sheet 24 can be formed from soft sheeted material such as asbestos or paper stock by rolling and pressing or it may be molded directly in shape from pulp or any type of mixed paper stock. Any of these materials are intended to be embraced within the term paper like material.

With either of these constructions the high frequency sounds tend to cause movement of the surface portion of the covering sheet and are also somewhat absorbed owing to the rough texture of the surfaces of the covering sheet. Low frequency sounds tend to move the membrane bodily causing the underlying material to compress and thus the structure as a whole presents efficient acoustical qualities.

What I claim is:

1. A structure for sound deadening or sound absorption comprising a facing member carrying a covering sheet consisting essentially of sheeted, paper-like material and having portions in contact with the facing member and portions raised relative thereto, the area of the raised portions being greater than the area of the portions in contact with the facing member, and a spacing member adapted to hold such facing member in spaced and cushioned relation to a wall member consisting essentially of soft, compressible'material.

2. A structure adapted for use for acoustical purposes comprising an underlying layer of com- 40 pressible material and a covering sheet consisting essentially of sheeted, paper-like material in part afiixed to the underlying material and in part raised relative thereto, the area of the raised portions of the covering sheet being greater than the area of the portions affixed to the underlying material.

3. A structure adapted for use for acoustical purposes comprising an underlying layer of compressible material and a covering sheet consisting essentially of sheeted, paper-like material which is attached to the underlying material through portions lying in a common plane and having portions raised relative thereto, the area of the raised portions being greater than the area of the portions lying in a common plane with the underlying material.

4. A structure as specified in claim 3 in which the covering sheet is aflixed to the underlying compressible material through .the medium of an intermediate sheet.

5. A structure for sound absorption, comprising an underlying layer of compressible material and .a covering sheet consisting essentially of sheeted, 

